Temperature-indicating system and apparatus for internal-combustion engines.



H. HLBOYCE. TEMPERATURE INDICATING'SYSTEM AND APPARATUS FOR INTERNAL COMBUSTILN ENGINES.

APPLICATION FILED AUG-3Q. I916.

Patented Nov. 28, 1916- 4 6 J I n.

0 G I I z o I Z J l I I 0 u FIG 5 TFIGE ator;

HARRISON H. BOYCE, OF FOREST HILLS, NEW YORK.

TEMPEBATURE-INDICATING SYSTEM AND APPARATUS FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Nov. 28, 1916.

Original application filed June 20, 1914, Serial No. 846,247. Divided and this application filed August 30,

l 1916. Serial No. 117,595.

To all whom it may concern Be it known that I, ITARRISON H. Boron, a citizen of the United States, residing at Forest Hills, in the poil'nty-of Queens and State of New York; have invented certain new and useful Improvements in T emperature-Indicating Systems and Apparatus for place directly in the engine cylinders, practically in the form of an explosion.- very high temperatures being attained. The temperatures of the various parts of theengine, however; mustbe; kept within limits or serious consequences will follow,-preventing v the proper operation of the engine or even leading to its serious injury. It is necessary for this purpose to provide means for cooling the engine so as to dissipate the excess of heat, the most common construction for this purpose consisting of a water circulation cooling system. As usually employed this system comprises a series of water jackets about the engine cylinders and a radiator connected with the water jackets, a circulation of the cooling water being maintained through the cylinder jackets and radiator by means of a pump or by gravity as in the well-known thermo-siphon systems. The water enters the jackets at one point usually at the lower end, circulates around the cylinders and passesout through the return pipe which conveys the water to the radi- The water then )asses through the radiator where it is cooled and then is returned to the cylinder jackets through the inlet pipe. Any overheating of the engine quickly results in raising the temperature of the circulating water, particularly the water leaving the jackets and the tempera ture of the cooling water at this point, therefore, forms an index of the thermal COIl(ll tion of the engine.

Overheating may result from a variety of causes such as insufhcient lubrication of the: cylinders, resulting 1n friction between the pistons and cylinders, which places an excessive load on the engine causing it to heat; insufficient lubrication of the-bearings producing like results; too rich a mixture of fuel and air which produces an excessively high temperature of combustion; insufliciency of the cooling system; stoppage in the circulation of the cooling water, either from some obstruction or breakage of the circulating pump; deficiency of the water in the cooling system; or defective circulation of air through the radiator such as may result from the breaking or slipping of the fan belt.

Among the results which may follow from overheating are "seizing" of the pistons within the cylinders, which may also result in the breaking of the crank shaft or the cracking of a cylinder; burning out of the bearings of the engine; and premature ignition owing to the high temperature within the combustion chamber. Several of the causes of overheating are progressive in their nature, such as insufficient lubrication of'the cylinders or bearings, as.this not only results in friction which causes overheating but the overheating itself further interferes with the lubrication as by burning the oil in the cylinders which aggravates the difficulty. Unless then, the initial causes of the trouble are quickly cured, serious.con sequences will follow, although usually if the engine is promptly stopped and the un favorable conditions corrected; actual injury to the mechanism may be avoided. It is, therefore, apparent that some means for determining the thermal conditiohof the engine is of the greatest value in securing the safe and proper operation thereof and further, that the desired indication of temperature may be obtained by properly measuring the temperature of the cooling water.

Not only is it desirableto secure an indication of excessively high temperatures "1 internal combustion engines but it is als, a great advantage to be able to guard against the temperature becoming too low. Thus in extremely cold weather, there is danger when theengine is not running of the cooling water freezing, which may result in bursting the radiator or even cracking the cylinder jackets. It is also important to maintain the temperature of the engine at as high a point as is compatible with safety Lfrom overheating as agreater efiiciency in I the use of fuel is thereby obtained and a smoother and more satisfactory operation of the engine results." For the. most satisfactory operation of the engine,'therefore, its temperature should be maintained as high as is practicable without encountering the dangers and objections of excessive heating. In the ordinary water-cooled motor, this condition usually obtains when the temperature of the cooling water upon leaving the cylinder jackets is slightly below the boiling point. \Vhen the water is at this temperature the engine will be operated economically and satisfactorily and at the same time, the cooling water does not boil away as would be the case if the boiling point were exceeded and is thereby enabled to perform properly its cooling function. The formation of steam by the boiling of the cooling water may, therefore, be considered as indicating a condition of probable danger requiring the immediate attention of the operator.

In accordance with the present invention, I provide accurate and convenient means for indicating to the operator of the vehicle at all times the thermal condition of the engine as shown by the temperature of the cooling water and advising him at once of the reaching of a condition of boiling and steam formation.

1 have found that the temperature of the water in the cylinder jackets varies greatly in different parts of the jackets, being ordinarily coolest at the lower ends whereit enters and gradually becoming heated, reaching its highest temperature only after it has surrounded the hottest part of the cylinder which is adjacent to the head and exhaust valve thereof, this part of the cylinder being where the ignition of the fuel charge takes place and where the high est temperature of combustion is reached. As explained above, the condition of danger in the-operation of the engine corresponds for practical purposes with a condition in which the water in the jacket boils, resulting in the formation of steam. It is highly desirable, therefore. to have an indication immediately upon the formation of steam in whatever part of the jacket this may take place. I have discovered that by providing means responsive to temperature changes and locating the same in the cooling system at or above the upper ends of the cylinders or at least as high as the combustion chambers thereof, the results desired are secured, as with this location of the temperature responsive element, it is not only subjected to the hottest water temperature,

but as any steam formed immediately rises.

it is also in a position to be influenced by steam formed in any part of the cylinder jacket.

In my Patent No. 1,090,776, dated March 17, 1914, I have disclosed a system and apparatus for indicating the thermal condition of an internal combustion engine em bodying the use of a device having a .temperpture-responsive element located in the air space above the. normal level of the water in the system, as set forth in said patent. I am by these means enabled to obtain a relative indication of the temperature of the cooling water and also obtain a danger signal immediately upon the formation of steam in the system which steam passes into the air space. thus causing a sudden increase in the temperature indication of the instrument. This construction does not normally give the actual water temperature but indicates a temperature somewhat lower than that of the water until the formation of steam takes place. For many purposes, the invention of this patent is most desirable and satisfactory, but under some conditions it is preferable to indicate the actual temperature of the heated water in the system. My present invention provides means whereby this actual hot water. temperature is indicated at all times and which will also be subjected to the action of any steam which may form in the system. Thus. with this invention, it is possible to secure an indication of actual water temperature without sacrificing the advantages of obtaining immediate knowledge of a condition of danger suggested by the formation of steam.

In the accompanying drawings, which form a part of this specification, and which illustrate one preferred embodiment of my invention, Figure 1 is a diagrammatic side elevation of the engine. radiator and connections, and portion of the dash of a motor vehicle showing the applicationof my invention thereto, a part of one cylinder being showirin section. Fig. '2 is a vertical sectional view through the indicating instrument. Fig. 3 is a front view of the instrument, parts being broken away to show the interior construction.

Referring to the drawings in detail, the numeral 1 designates an automobile engine provided with the cylinders 2 in which work the pistons 3. Each of the cylinders is surrounded by a water jacket 4, which is connected by a branch pipe 5 with the main re.- turn pipe 6. The latter discharges the water into the radiator 7 through which the water passes in small streams and is subjected to currents of air forced through the radiator by the movement of the vehicle, usually asisted by a fan 8 as is customary in motor vehicle construction. The water when cooledpasses from the bottom of the radiator to the lower portions of the cylinder jackets through the inlet pipe 9 and branches 10. The circulation of the water may be maintained by any suitable means. as by means ofthe circulating pump I1.

As the ignition and combustion or explosion strokes, it will be seen that these portions of the cylinders constitute combustion chambers (designated by the numeral 12) where the greatest temperature is reached. The cooling water, therefore, does not reach its maximum temperature until it reaches the part ofthe water jacket surrounding the combustion chamber. The exhaust valves of the cylinder are also located at the upper ends thereof, as is well-known and the hot gases rushing out through these valves when opened further contributes to make this part of the cylinder the hottest. Preferably, therefore, I provide means for taking the temperature of the cooling water at or after it has passed this hottest region so as to get its maximum temperature.

The engine described is shown as inclosed beneath the usual hoodla"), the vehicle being provided with a dash or instrument board 16 which forms a part of the vehicle body 17 and which as is customary is located immediately in front of the drivers seat so that instruments placed thereon may be readily observed by the driver when operating the car.

In accordance with the present invention, I provide a devicehaving a part responding to temperatures in the cooling' system and having means for indicating. such temperae tures located in such a. way a'sf'to be, under the constant observation-of" thedriver, such I indicating means being preferably locatedon, the. dash or instrument board where the 3 other instruments necessaryyforthe opera.-

tion of the car, such as the speedometerand ammeter, are customarily placed. accomplish this result by employing means having a temperature responsive element which may be located in a part of the cooling system where it will be influenced bythe temperature ofthe cooling water, preferably after the water has reached its highest temperature or of any steam which may form in'the jackets, and an-indicating in-.

strument located upon the dash, of such a character that it may easily be observed by the driver; these two instrumentalities being opei'atively connected by means which will cause the indicator to indicate the temperature to which the temperature responsive element is subjected, the operative connection being such that it will not. be destroyed or affected by the decidedly severe andspecial conditions which exist ina motor vehicle.

The construction which I have illustrated and which complies with the requirements named comprises a temperature responsive element 20 in the shape of a bulb filled with an expansible fluid, this bulb being located in the cooling system preferably in such a place as to be influenced by the cooling water after it has attained its highest temperature-and where it will'be subjected to the action of any steam which may form in the jackets. In the specific embodiment shown the bulb is mounted in the return pipe, which conveys to the radiator the hot water leaving the upper ends of the cylinder jackets the bulb being preferably located at a by the steam formed in the jackets of any of the cylinders. This bulb is connected by a flexible tube 21 of suitable material havinga bore filled with the expansible fluid, with the indicating instrument 22, which is illustrated as being mounted on the dash 16.

This instrument comprises a Bourdon tube 23, with the interior of which the bore of the flexible tube communicates, the free end of' the Bourdon tube being connected by suitable mechanism to the indicating member or hand 24. As illustrated the end of the tube is connected to a lever fulcrumed [on a pivot 26, the other end of the lever being connected to the hand. The increase of. temperature of the cooling water will cause the fluid 'in the bulb 20 to expand, which will force the column of fluid to movein the tube 21 producing an increase of pressure'in the Bourdon tube 23. This increase iiipressure results in accordance with the well-understood inode of operation of a Bourbon tube in a tendency for the latter to straighten out causing a movement of. thefree end of the tube, which operates through the lever 25 to actuate the hand 2;. Conversely a? cooling of the water will cause "the fluid in the bulb to contract thus relieving the pressure'in the Bourdon tube and permitting the hand to return toward its initial position. The, l3ourdon tube and hand are preferably inclosed in a suitable casing 30, the hand moving over a suitably divided dial plate 31. Preferably the front of the instrument is closed by a cover 32 having a window 33 therein, through which the movements of the hand over the scale may be observed.

It will be understood that any desired temperature measuring and indicating means may be used employing any suitable form of.temperattire-responsive element or indicating devices other than such as above described.

lt.-will be seen that with the construction described, a temperature responsive means is provided which'is located in the most effective position to respond to the temperature changes which it is desired to indicate and an indicating means is also provided which is located in a most convenient position for observation by the driver, namely, on the instrument board or dash of the vehicle. The use of the flexible connecting tube between these two instrumentalities is most important as making this arrangemenfi possible and as producing an operative (evice which shall not be subject to damage or unfavorable influence, owing to the peculiar conditions of use. .These severe conditions which must be dealt with include the continuous vibration of the motor necessarily resulting from its operation, and of which vibration the temperature responsive element partakes, and the independent or secondary vibration of the instrument board or dash which it receives indirectly from the motor through the vehicle frame and body, and also the working or twisting to which the dash as a part of the vehicle body is necessarily subjected due to the strains resulting from the rapid movements of the vehicle over uneven road surfaces. The vibrations set up in various parts of the vehicle body by the engine are less acute than, and do not ordinarily correspond in amplitude and phase with the vibrations of the engine itself as they are influenced by the natural periods of vibration of the several body parts; also as the vehicle frame and body cannot be made absolutely rigid,-;thc strains incident to movements of' the vehicle necessarily result in the relative movement of the various parts of the vehicle.

Thus it will be seen there isa tendency to constant relative displacement of more or less extent between the dash or any part of the vehicle body and the engine. The use of the flexible tube compensates for all of these movements and permits them to take place without destroying the responsive nature of the operative connection between the temperature responsive element aml the indicating instrument. Furthermore, in an instrument of the character described. the Bourdon tube.and hand are necessarily of more or less light or fragile construction and unable to withstand continuous sharp vibrations such as are produced in the motor itself and in fact such vibrations would tend to make accurate reading of the instrument impossible as the hand would be continually in motion. Therefore, it is important that the direct and sharp vibrations of the motor be not positively transmitted to the indicating instrument as through a rigid, metallic connection. The use of a flexible tube prevents this and permits the instrument to indicate accurately as the vibrations and IIIOVGll'lBlltS to which it is subjected indirectly through the vehicle body are of a different character from those emanating directly from the engine and are not such as to prevent its satisfactory operation. The use of the flexible tube also permits the location of the temperature responsive element in such part of the coolingsystem as is most desirable to produce tennmraturc indication which is most responsive to the thermalconditiohs of the engine and it also permits the same type of shall respond to maximum temperatures existing in the system and not to some lower at temperature. Obviously a condition of danger is suggested if the boiling I point is reached in any part of the system and the maximum temperature of the water in the system should, therefore, govern the indication. This is accomplished by niy'invcntion by locating the temperature responsive element in the upper part of the system as it will there be subjected to the waten after it has reached the hottest part of the cylinder and it will also be subjected to steam formed in any part of the jacket as such steam will immediately rise and so necessarily reach the temperature responsive element. w

The location of the indicating intrument in a position near to the driver such. as on the dash or instrument board has particular utility in connection with devices indicating the" actual temperature of the cooling water for the reason that the changes in the temperature of the water are. more or less gradual and consequently the indications of the instrument vary niore or less gradually up to aml including the danger point indicated by the temperature of boiling. This continuous temperature change indication must. therefore, be observed by the driver and this can best be accomplished when the indicating instrument is located in convenient proximity to him.

The Bourdon tube type of instrument described is particularly well fitted to the purposesof the present invention as the movement of the indicating hand produced by the operation of the Bourdon tube of this ,construction naturally has a very open scale in the upper ranges of its movement: that is to say at the high temperatures and at or near the danger point relatively small chan es irecting the operators atsomewhat similar perature conditions prevail in the case of other motor "ehicles provided with internal combustion engines. My invention, it will be seen therefore, is applicable in connection with vehicles of various types and is not to be understood as limited to automobiles or vehicles adaptedto travel only on the surface of the earth but is of general application to internal combustion vehicle propelling motors.

While I have shown and described one preferred embodiment of my invention, it will be understood that various changes in the location and construction of the parts may be employed and I do not, therefore, desire to limit myself to the embodiment shown, but intend to cover my invention broadly in whatever form its principle may be embodied.

This case is a division of my application Serial No. 846,247, filed June 20th, 1914.

Having thus described my invention, I claim:

1. In temperature indicating means for water-cooled internal combustion motors of motor vehicles, the combination with the water circulation cooling system, of a temperature responsive element located in a position to be influenced by the temperature of the cooling liquid on its way to the radiator after it has been affected by the temof the combustion chamber of a cylinder, an indicating instrument located in a position to be observed by the driver, when operating the vehicle and an open-a tive connection between the temperature responsive element and the indicating instrument.

2. In temperature indicating means for water cooled internal combustion motors of motor vehicles, the combination with a motor and the water circulation cooling system thereof, of a temperature-responsive element located in said system above the level of the hottest part of a motor cylinder, and in a position to be normally in contact with the cooling liquid after it has been heated by such hottest part, and to be subjected to contact with any steam which may be generated in the system due to the heat in the cylinder, and temperature-indicating means observable by the driver when operating the vehicle, said temperature indicating means being controlled by the temperature of said temperature-responsive element.

3. In a temperature indicating means for multiple cylinder, internal combustion vehicle propelling motors, having a water circulation cooling system including a plurality of cylinder jackets, a radiator, and a return pipe for conveying the heated water from a plurality of said jackets to said radiator, the combination with said return )i e of a tem )erature-res onsive element located in a part of said return pipe where itwill be influenced by the temperature of the water coming from a plurality of said jackets, and means controlled by aid element and observable by the driver lwhen operating the vehicle for indicatin" changes in the temperature of said eleme'i l. In temperature indicating means for multiple cylinder internal combustion vehicle propelling motors having a water circulation cooling system, including a plurality. of cylinder jackets, a radiator, and a return pipe connecting the upper ends of the cylinder jackets with the radiator, the combination with said return pipe, of a temperature responsive element located in said return pipe between said cylinder jackets and said radiator, said temperature-respom' sive element being at a higher level than the upper ends of said cylinder jackets, and means controlled by said element and observable by the driver when operating the vehicle for indicating changes in the temperature of said element.

5. In temperature indicating means for internal combustion vehicle propelling motors having a water circulation cooling system in which the water circulation is upward in the cylinder jackets and leaves the jackets at the upper ends thereof, the combination with the cooling system, of a bulb immersed in the circulating water in the upper portion of, the system where it will be subjected to contact with steam formed in any part of a jacket and to the temperature of the water after it has reached the hottest-part of the cylinder, an indicating instrument located on the vehicle dash and comprising a pressure responsive element and an indicating member, a flexible tube connecting the bulb and pressure responsive element, and an ex ansible fluid filling the bulb and flexible tube.

6. In temperature indicating means for multiple cylinder internal combustion ve hicle propelling motors having a water circulation cooling system, including a plurality of cylinder jackets, a radiator, and a return pipe for conveying the hot water from the upper parts of the jackets to the radiator, the combination with the cooling system of a bulb located in said return pipe where it will be influenced by the hot water or steam coming from aplurality of said cylinder jackets, an indicating instrument located on the vehicle dash-and comprising a pressure responsive element and indicating means, a flexible tube connecting the bulb and pressure responsive element and an expansible fluid filling the bulb and flexible tube.

HARRISON H. BOYCE. 

